In the CA (Carrier Aggregation, carrier aggregation) technology, multiple continuous or discontinuous carriers are aggregated into greater bandwidth (100 MHz at most), so as to satisfy a requirement for a higher rate and improve utilization of discrete spectrum.
As an important evolution solution, a HetNet (Heterogeneous Network, heterogeneous network) implements accurate coverage of a mobile communications network, which notably improves network performance, and brings better voice and mobile data service experience to a user. A network side of the HetNet may include a core network, a transmission network, and a base station; user equipments communicating with the network include a UE (User Equipment, user equipment) having a CA capability and a UE not having a CA capability.
Using the UE having a CA capability as an example, when the HetNet transmits data in a CA manner, an EPC (Evolved Packet Core, evolved packet core) network delivers data information to the UE by using both a primary base station and a secondary base station, and the UE needs to send a feedback to the primary base station, where the feedback is used for indicating receiving situations of the data information delivered by the primary base station and/or the secondary base station. In the prior art, the secondary base station allocates PDSCH (Physical Downlink Shared Channel, physical downlink shared channel) and PDCCH (Packet Data Control Channel, packet data control channel) resources to the UE, and requests, from the primary base station, a data block to be sent to the UE; after receiving the data block delivered by the primary base station, the secondary base station determines an identifier of a PUCCH (Physical Uplink Control CHannel, physical uplink control channel) code channel resource; the secondary base station sends the identifier of the PUCCH code channel resource to the primary base station, and meanwhile sends the data block and the identifier of the PUCCH code channel resource to the UE; the UE sends a feedback for the data block on a corresponding PUCCH code channel resource according to the identifier of the PUCCH code channel resource; the primary base station may demodulate the feedback after receiving the feedback on a corresponding PUCCH code channel according to the identifier of the PUCCH code channel resource. Feedbacks obtained by means of the demodulation may include two types: an NACK (Negative Acknowledgement, negative acknowledgement) and an ACK (Acknowledgement, acknowledgement), and the secondary base station needs to perform HARQ (Hybrid Automatic Repeat Request, hybrid automatic repeat request) retransmission on data corresponding to the NACK. However, transmission efficiency in the foregoing data transmission process is relatively low.